Prelude L4-2056cc DOHC (1990)
Main Relay (Computer/Fuel System): Description and Operation
Main Relay
The main relay, located under the left side of the dashboard, actually contains two individual relays.
One relay is energized whenever the ignition is on, and it supplies the battery voltage to the ECU, power to the injectors, and power to the second relay.
The second relay is energized for 2 seconds when the ignition is switched on before starting, and when the engine is running, to supply power to the fuel
pump.